The present invention relates to a scan driver, an electro-optical device and drive method.
A liquid crystal panel is used as a display section of an electronic instrument such as a portable telephone. In recent years, a still image and a video image containing valuable information have been distributed accompanying widespread use of portable telephones. Therefore, an increase in the image quality of the liquid crystal panel has been demanded.
An active matrix liquid crystal panel using a thin-film transistor (hereinafter abbreviated as “TFT”) is known as a liquid crystal panel which realizes an increase in the image quality of the display section of the electronic instrument. The active matrix liquid crystal panel using the TFT realizes high response time and high contrast in comparison with a simple matrix liquid crystal panel using a dynamically driven super twisted nematic (STN) liquid crystal, and is suitable for displaying a video image or the like. Japanese Patent Application Laid-open No. 2002-351412 is known as a conventional example.
However, since the active matrix liquid crystal panel using the TFT consumes a large amount of electric power, power consumption must be reduced in order to employ the active matrix liquid crystal panel as a display section of a battery-driven portable electronic instrument such as a portable telephone. An interlace drive method which reduces power consumption is known. A comb-tooth drive method which reduces coloring errors in each display pixel is also known. The interlace drive method is a drive method suitable for displaying a still image, since the image quality is decreased when applied to a video image.
Therefore, a driver circuit which can deal with various drive methods such as normal drive, interlace drive, and comb-tooth drive is demanded for a display panel (liquid crystal panel, for example) which displays a still image and a video image.